[dm-devel] [RFC PATCH 0/7] speeding up mpathpersist

Martin Wilck mwilck at suse.com
Fri May 17 22:56:56 UTC 2019

We've had reports that mpathpersist doesn't scale well in environments
with lots of IO devices. This patch set tries to address this problem
with a few optimizations:

 - instead of doing a full path discovery at startup, only look at
   paths that are part of the maps being worked on
 - allow multiple PR commands in a single run using "batch files",
   without re-discovering everything between PR commands
 - avoid looking at priorities

I've done some basic testing and it seems to work. It remains to be
seen what the effect on performance really is.


Martin Wilck (7):
  mpathpersist: call usage() just once on return
  mpathpersist: add option --batch-file (-f)
  mpathpersist: no need to treat error close() as fatal
  libmpathpersist: updatepaths: deal with missing pp->udev
  libmpathpersist: factor out initialization and teardown
  mpathpersist: initialize data structures only once
  libmpathpersist: don't bother with priorities

 libmpathpersist/mpath_persist.c | 250 +++++++++++++++-----------------
 libmpathpersist/mpath_persist.h |  40 +++++
 mpathpersist/main.c             | 218 +++++++++++++++++++++-------
 mpathpersist/main.h             |   1 +
 4 files changed, 320 insertions(+), 189 deletions(-)


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